Hearing aid



FIG. 1 is a top perspective view of a hearing aid, including a behind-the-ear piece, a receiver assembly, and a dome, according to the present invention;

FIG. 2 is a side perspective view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is a rear view thereof; and,

FIG. 8 is a front view thereof.

The broken lines in the drawing views are included for the purpose of illustrating portions of the hearing aid that form no part of the claimed design. 

The ornamental design for a hearing aid, as shown and described. 